1. Field of the Invention (Technical Field):
The invention relates to a joystick having more than two degrees of freedom, at least designed for movement in the x and y direction at right angles to a longitudinal axis thereof, and in a rotational direction around said longitudinal axis.
2. Description of Related Art:
Such a joystick is known from the European patent specification EP-B-O 790 488.
The known joystick is moveable in the x and y direction as well as in a rotational direction around the axis of the joystick, and is used for controlling a helicopter.
To determine the movement of the joystick in the rotational direction it possesses a detector that uses light signals, and an identifiable mosaic pattern working together with these light signals, wherein the rotational movement of the joystick can be derived through the detection of said pattern. As already known, the movement in the x and y direction can be determined by using electromagnetic means.
In practice, there is a demand for an inexpensive joystick that can be used for the training of hand-eye coordination such as is relevant for endoscopic operations and virtual endoscopy.
To this end the U.S. patent application 2001/00209737 proposes a device in accordance with the preamble, which possesses a fourth degree of freedom in the direction of the longitudinal axis.
The device known from this publication is provided with a handle for manual operation.
From DE-A-19736086, a joystick according to the preamble is known, which comprises a first tubular member surrounded by a second tubular member, wherein the first tubular member is designed for movement in the x and y direction and wherein the second tubular member is designed for sliding along and rotating around the first tubular member.